THE VESICULOSA. 373 



appears to be of universal distribution. But the most 

 gigantic in the tribe are found in the genus Mydas, 

 which are likewise insects of prey, and sometimes nearly 

 two inches long. The third and fourth tribes, the Hyho- 

 tidcB and Empid<B, still retain the sanguinary habits of 

 the preceding; but they are much smaller insects; and 

 the latter, especially, have usually very elongated rostra, 

 and seize their prey in flight, although they do not dis- 

 dain the nectar of flowers. In this same tribe, the Hi- 

 larcB are peculiar for the dilatation of their anterior tarsi 

 in the males; and they have the habit of dancing upon 

 the surface of the water in brooks and ponds without 

 any fear of submersion. The present is a large tribe, 

 consisting of many genera of small insects. 



(334.) The fifth tribe, or the Vesiculosa, are re- 

 markably gibbous insects, with very minute heads, 

 which are nearly lost in comparison with the rest of 

 the body, and almost wholly occupied by their eyes ; 

 and they have also lengthy rostra, although in some it 

 is nearly obsolete. Their wings, in repose, are placed 

 in a sort of roof over the body. These insects are all 

 attached to flowers, and their preliminary stages are 

 unknown. The sixth tribe, or NemestrinidcB, have a 

 considerable resemblance to the BomhyUi, — from which, 

 however, the peculiar neuration of their wings estranges 

 them ; for in these organs they closely resemble Mydas: 

 the two genera known are exotic and rare insects. The 

 seventh tribe comprises the Bornbyliidae, which are 

 distinguished for their short hairy body and lengthy 

 proboscis, which is sometimes considerably longer than 

 the insect. They have usually great power of flight, 

 and accomplish it with remarkable velocity ; and many 

 of them take their food, like some of the sphinges and 

 humming-birds, whilst hovering over the flower which 

 contains it. They consist of several genera, the most 

 of which are exotic. The eighth and last tribe of the 

 Tetrachjet^ tanvstoma, consists of the Anthracidce., 

 — insects almost wholly remarkable for their intensely 

 black colour, and beautiful wings, variegated with 



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